Carbonic Anhydrases: The sequences of the high and low activity equine isozymes will be completed and evaluations made of the number of alleles controlling the synthesis of the B form in terms of 7 amino acid substitutions noted. The ability of those carbonic anhydrases containing more than 1 cysteine residue to form mixed disulfides with glutathione will be extended to possible tissue interactions of this nature. Metalloproteins: Variations in properties of human superoxide dismutase from the bovine enzyme due to the presence of an additional cysteine residue and 4 amino acid C-terminal extension will be studied. Immunoglobulins: Possible relationships of specific human lambda C region substitutions with hypervariable lambda V region sequences will be probed. Correlations of the X-ray structures of crystalline McG-IgG and Mcg-BJA with the V-region sequences of both the H and L-chains will be extended. Searches for myeloma proteins with antibody activity will be continued. Alpha-Fetoproteins: The partial sequences of large peptide fragments of the human protein and their relationships to serum albumin will be determined. The ability of the larger peptides to bind fatty acids and estradiol will be explored. BIBLIOGRAPHIC REFERENCES: Fett, J.W., and Deutsch, H.F., The Variability of Human Lambda-Chain Constant Regions and Some Relationships to V-Region Sequences. Immunochemistry 13: 149, 1976. Edmundson, A.B., Ely, K.R., Abola, E.E., Schiffer, M., Panagiotopoulos, U., and Deutsch, H.F. Conformational Isomerism, Rotational Allomerism, and Divergent Evolution in Immunoglobulin Light Chains. Fed. Proc. 35: 2119, 1976.